1. Field of the Invention
The present invention relates to a character output device, such as a printer, which retains a plural number of fonts in advance and carries out a character output process. More particularly, the invention relates to a character output device which is able to automatically select the font closest to a font the use of which is requested, when the same font as the use requested font is not retained in the character output device.
2. Discussion of the Related Art
When a conventional character output device, such as a printer, outputs a character using a font that is not contained in the list of the fonts retained therein, it uses a previously designated font for outputting the character.
The use of the outline font succeeds in reducing the memory capacity of the storage for storing fonts in the character output device, and hence enables the device to retain a plural number of fonts.
When one of the fonts that are retained by the character output device (These fonts will be referred to as device fonts.) is requested for character outputting, a previously designated font, not closest in typeface to the use requested font, is used for outputting the character. Accordingly, the device fonts are inefficiently utilized. In other words, even if a font resembling the use requested font is contained in the list of the fonts of the character output device, the device is compelled to use the previously designated font. The result is the outputting of the character of the font quite different from the use requested font.
To solve the problem, a technique is disclosed in Japanese Patent Unexamined Publication No. Sho. 60-80895. In the technique, the properties of the use requested font are supplied to the character output device. The device selects the font the properties of which are closest to those of the use requested font, and outputs a character of the selected font.
In the publication, character set, typeface of character, character size, character inclination, and character thickness are used for the properties of the font used.
Another technique is disclosed in Japanese Patent Unexamined Publication No. Hei. 6-59851, and calculates differences between the values of specific properties of a use requested font and the values of specific properties of a device font, selects the font closest to the use requested font on the basis of the calculation results, and uses the selected font for character outputting.
In the publication, character thickness, character inclination, average character width, and the like, which define an external appearance of the character, are used for the properties of the font used.
In designating a typeface of character to be outputted from the character output device, a user usually designates it while referring to the typefaces of characters on the screen of the device on which he edited a document. In this case, the properties of the designated font are referred to and a font is selected on the basis of the reference on the character output device and processed for outputting.
The font designated on the device that the user used for editing is often not contained in the list of those fonts retained in the character output device. In this case, the properties of the designated font are referred to, and the font on the character output device, which is closest to the designated font, is selected.
It is not always to properly select a font close to the font intended by the user even if the properties of the font disclosed by Japanese Patent Unexamined Publication Nos. Sho. 60-80895 and Hei. 6-59851 are used.
As for the character thickness as one of the properties of the font, if the character thickness of the font, such as the bold face of the light face of the font, is known, the conventional art cannot know an exact value of the character thickness of the bold face. Accordingly, it is impossible to exactly grasp the typefaces of a bold face and another bold face.
For the line width of a character as one of the properties of the font, in some typefaces of characters, for example, the printed style, the line width varies during one stroke of writing. In such a style of character writing, the properties of the typeface per se, viz., the design features of the character, are difficult to qualitatively measure. If an average value, for example, of the line width is used instead, it often fails to exactly describe the design features of the character. Particularly, in the case of a style of character writing with a brush, the line width varies. The properties of that typeface is further difficult to express. Accordingly, it is impossible to exactly discriminate the likeness between the typefaces.
An imagery caused by a typeface design of a character frequently depends a form proper to a character. A character of which the counter is broad gives rise to a somewhat casual imagery, and a character with serifs gives rise to a solid imagery and hence is suitable for formal documents. The judgement based on only the properties of the character thickness, line width and the like fails to exactly discriminate the imagery difference.